{"id":"CVE-2026-114501","aliases":["BIT-pillow-2026-114501","CLSA-2026-1793025111","CLSA-2026-1793101237","DEBIAN-CVE-2026-114501","EUVD-2026-107575","GHSA-654x-cwwv-5j9c","PYSEC-2026-4336","UBUNTU-CVE-2026-114501","openSUSE-SU-2026:22246-1"],"status":"published","title":"Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT \u003e 1","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0037,"percentile":0.31312,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-226","CWE-908"],"published":"2026-10-21T21:17:09Z","modified":"2026-11-11T17:27:05Z","fixes":[{"ecosystem":"PyPI","package":"pillow","fixed_in":["13.0.0"],"sources":["ghsa","osv"]},{"ecosystem":"Bitnami","package":"pillow","fixed_in":["13.0.0"],"sources":["osv"]},{"ecosystem":"TuxCare:PyPI","package":"pillow","fixed_in":["11.2.1.post14+tuxcare"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.2.1"},{"fixed":"13.0.0"}]}]},{"source":"osv","ecosystem":"Bitnami","package":"pillow","ranges":[{"type":"SEMVER","events":[{"introduced":"11.2.1"},{"fixed":"13.0.0"}]}]},{"source":"osv","ecosystem":"TuxCare:PyPI","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.3.0"},{"fixed":"11.3.0.post12+tuxcare"}]}],"versions":["11.3.0","11.3.0.post1+tuxcare","11.3.0.post10+tuxcare","11.3.0.post11+tuxcare","11.3.0.post2+tuxcare","11.3.0.post3+tuxcare","11.3.0.post4+tuxcare","11.3.0.post5+tuxcare","11.3.0.post6+tuxcare","11.3.0.post7+tuxcare","11.3.0.post8+tuxcare","11.3.0.post9+tuxcare"],"bundled":3},{"source":"osv","ecosystem":"TuxCare:PyPI","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.2.1"},{"fixed":"11.2.1.post14+tuxcare"}]}],"versions":["11.2.1","11.2.1.post1+tuxcare","11.2.1.post10+tuxcare","11.2.1.post11+tuxcare","11.2.1.post12+tuxcare","11.2.1.post13+tuxcare","11.2.1.post2+tuxcare","11.2.1.post3+tuxcare","11.2.1.post4+tuxcare","11.2.1.post5+tuxcare","11.2.1.post6+tuxcare","11.2.1.post7+tuxcare","11.2.1.post8+tuxcare","11.2.1.post9+tuxcare"]},{"source":"osv","ecosystem":"Debian:12","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10.0.0-1","10.1.0-1","10.2.0-1","10.3.0-1","10.3.0-2","10.4.0-1","10.4.0-1.1","11.1.0-1","11.1.0-2","11.1.0-3","11.1.0-4","11.1.0-5","11.2.1-1","11.3.0-1","12.0.0-1","12.1.0-1","12.1.1-1","12.1.1-2","12.2.0-1","12.3.0-1","13.0.0-1","9.4.0-1.1","9.4.0-1.1+deb12u1","9.5.0-1"]},{"source":"osv","ecosystem":"Debian:13","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.1.0-5","11.1.0-5+deb13u1","11.1.0-5+deb13u2","11.1.0-5+deb13u3","11.1.0-5+deb13u4","11.2.1-1","11.3.0-1","12.0.0-1","12.1.0-1","12.1.1-1","12.1.1-2","12.2.0-1","12.3.0-1","13.0.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.1.0-5","11.2.1-1","11.3.0-1","12.0.0-1","12.1.0-1","12.1.1-1","12.1.1-2","12.2.0-1","12.3.0-1","13.0.0-1"]},{"source":"osv","ecosystem":"PyPI","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.2.1"},{"fixed":"13.0.0"}]}],"versions":["11.2.1","11.3.0","12.0.0","12.1.0","12.1.1","12.2.0","12.3.0"]},{"source":"osv","ecosystem":"PyPI","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.2.1"},{"fixed":"13.0.0"}]}],"versions":["11.2.1","11.3.0","12.0.0","12.1.0","12.1.1","12.2.0","12.3.0"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"pillow-python2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.2.1-3~build1","6.2.1-3","6.2.1-3ubuntu0.1~esm1","6.2.1-3ubuntu0.1~esm2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["12.1.1-2ubuntu1","12.3.0-1ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.3.0-1ubuntu1","11.3.0-1ubuntu2","12.0.0-1ubuntu1","12.1.1-1ubuntu1","12.1.1-2ubuntu1","12.1.1-2ubuntu1.1","12.1.1-2ubuntu1.2","12.1.1-2ubuntu1.3","12.1.1-2ubuntu1.4"]},{"source":"osv","ecosystem":"openSUSE:Leap 16.0","package":"python-Pillow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"11.3.0-160000.9.1"}]}],"bundled":39}],"products":[{"vendor":"python","product":"pillow"},{"vendor":"python-pillow","product":"pillow"}],"references":[{"url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-654x-cwwv-5j9c","tags":["x_refsource_CONFIRM","exploit","Vendor Advisory","advisory","web","report"]},{"url":"https://github.com/python-pillow/Pillow/pull/10172","tags":["x_refsource_MISC","Issue Tracking","report","fix","web"]},{"url":"https://github.com/python-pillow/Pillow/commit/19f64946eb247b973dd4560be7dea3bf979d2e6a","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0","tags":["x_refsource_MISC","Release Notes","article","web","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-114501","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-654x-cwwv-5j9c"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114501.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-114501","tags":["advisory"]},{"url":"https://github.com/python-pillow/Pillow","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-114501","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-114501","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://bugzilla.suse.com/1286256","tags":["report"]},{"url":"https://bugzilla.suse.com/1286273","tags":["report"]},{"url":"https://bugzilla.suse.com/1286287","tags":["report"]},{"url":"https://bugzilla.suse.com/1286311","tags":["report"]},{"url":"https://bugzilla.suse.com/1286312","tags":["report"]},{"url":"https://bugzilla.suse.com/1286313","tags":["report"]},{"url":"https://bugzilla.suse.com/1286314","tags":["report"]},{"url":"https://bugzilla.suse.com/1286325","tags":["report"]},{"url":"https://bugzilla.suse.com/1286368","tags":["report"]},{"url":"https://bugzilla.suse.com/1286370","tags":["report"]},{"url":"https://bugzilla.suse.com/1286372","tags":["report"]},{"url":"https://bugzilla.suse.com/1286381","tags":["report"]},{"url":"https://bugzilla.suse.com/1286388","tags":["report"]},{"url":"https://bugzilla.suse.com/1286392","tags":["report"]},{"url":"https://bugzilla.suse.com/1286396","tags":["report"]},{"url":"https://bugzilla.suse.com/1286397","tags":["report"]},{"url":"https://bugzilla.suse.com/1286398","tags":["report"]},{"url":"https://bugzilla.suse.com/1286399","tags":["report"]},{"url":"https://bugzilla.suse.com/1286400","tags":["report"]},{"url":"https://bugzilla.suse.com/1286401","tags":["report"]},{"url":"https://bugzilla.suse.com/1286402","tags":["report"]},{"url":"https://bugzilla.suse.com/1286403","tags":["report"]},{"url":"https://bugzilla.suse.com/1286404","tags":["report"]},{"url":"https://bugzilla.suse.com/1286405","tags":["report"]},{"url":"https://bugzilla.suse.com/1286406","tags":["report"]},{"url":"https://bugzilla.suse.com/1286408","tags":["report"]},{"url":"https://bugzilla.suse.com/1286411","tags":["report"]},{"url":"https://bugzilla.suse.com/1286489","tags":["report"]},{"url":"https://bugzilla.suse.com/1286793","tags":["report"]},{"url":"https://bugzilla.suse.com/1286795","tags":["report"]},{"url":"https://bugzilla.suse.com/1286796","tags":["report"]},{"url":"https://bugzilla.suse.com/1286797","tags":["report"]},{"url":"https://bugzilla.suse.com/1286798","tags":["report"]},{"url":"https://bugzilla.suse.com/1286799","tags":["report"]},{"url":"https://bugzilla.suse.com/1286800","tags":["report"]},{"url":"https://bugzilla.suse.com/1286801","tags":["report"]},{"url":"https://bugzilla.suse.com/1286802","tags":["report"]},{"url":"https://bugzilla.suse.com/1286803","tags":["report"]},{"url":"https://bugzilla.suse.com/1286804","tags":["report"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112390","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112391","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112392","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112393","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112394","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112395","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112396","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112397","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112398","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112399","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112400","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112401","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112402","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112403","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112404","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112405","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112406","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112891","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112892","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112893","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112894","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112895","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112896","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112897","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112898","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112899","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112900","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112901","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-112902","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-114501","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96636","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96637","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96638","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96639","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96640","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96641","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96642","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96643","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-96778","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2026-114501","title":"Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT \u003e 1","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T21:17:09.748Z","modified":"2026-10-30T16:10:03.645Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-226","CWE-908"],"updated_at":"2026-11-02T13:39:50.160666Z"}],"euvd":[{"id":"EUVD-2026-107575","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T21:17:09Z","modified":"2026-10-30T16:10:03Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:59:05.913237Z"}],"ghsa":[{"id":"GHSA-654x-cwwv-5j9c","title":"Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT \u003e 1","description":"### Summary\n\nWhen [`PILLOW_ALIGNMENT`](https://pillow.readthedocs.io/en/stable/reference/block_allocator.html#memory-pools) is set above 1, exporting an image to Arrow returns uninitialized heap memory mixed in with the pixel data. That memory can include pixels from images the process freed earlier. \n\n### Details\n\nWith an alignment above 1, the default allocator pads each row up to `aligned_linesize` and starts the first row at an aligned offset into the block. It then exports `im-\u003eblocks[0].ptr` as `xsize * ysize` tightly packed pixels, so exported data includes the padding bytes, and can include a few bytes from before the first row.\n\nTested vulnerable on 11.2.1, 12.3.0, 4c1ed27a5.\n\n### PoC\n\nWhether things leak may depend on allocator configuration. This does show a leak on my Mac.\n\n```python\nimport os\n\nos.environ[\"PILLOW_ALIGNMENT\"] = \"64\"\n\nfrom PIL import Image\n\n# Image A: 64 px wide, so its rows fill the whole aligned stride\na = Image.new(\"L\", (64, 40), 0x41).transpose(Image.Transpose.FLIP_LEFT_RIGHT)\ndel a\n\n# Image B: 61 px wide, so each row has 3 bytes of padding; its pixels are all 0\nb = Image.new(\"L\", (61, 40), 0).transpose(Image.Transpose.FLIP_LEFT_RIGHT)\n\ntry:\n    exported = Image.fromarrow(b, b.mode, b.size).tobytes()\nexcept ValueError as e:\n    print(\"Not vulnerable:\", e)\nelse:\n    if leaked := len(exported) - exported.count(0):\n        raise RuntimeError(f\"{leaked} of {len(exported)} exported bytes are not B's pixels\")\n```\n\n### Impact\n\nInformation disclosure for applications that set `PILLOW_ALIGNMENT` and export images to Arrow. Likely any image whose row length isn't a multiple of the alignment will do. In a service handling several users' images, one user's exported data can contain pixels from another user's image, or other stale heap contents.","status":"published","published":"2026-10-23T21:53:21Z","modified":"2026-10-23T21:53:25Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-226","CWE-908"],"updated_at":"2026-11-02T14:41:35.723785Z"}],"nvd":[{"id":"CVE-2026-114501","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T22:16:49.41Z","modified":"2026-10-30T17:17:14.473Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-226","CWE-908"],"updated_at":"2026-11-02T14:13:02.371082Z"}],"osv":[{"id":"CVE-2026-114501","title":"Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT \u003e 1","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T21:17:09.748Z","modified":"2026-11-11T17:27:05.870270846Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-226","CWE-908"],"updated_at":"2026-11-11T17:46:38.239173Z"},{"id":"DEBIAN-CVE-2026-114501","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T22:16:49.41Z","modified":"2026-10-31T09:47:32.121826621Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:50.923612Z"},{"id":"GHSA-654x-cwwv-5j9c","title":"Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT \u003e 1","description":"### Summary\n\nWhen [`PILLOW_ALIGNMENT`](https://pillow.readthedocs.io/en/stable/reference/block_allocator.html#memory-pools) is set above 1, exporting an image to Arrow returns uninitialized heap memory mixed in with the pixel data. That memory can include pixels from images the process freed earlier. \n\n### Details\n\nWith an alignment above 1, the default allocator pads each row up to `aligned_linesize` and starts the first row at an aligned offset into the block. It then exports `im-\u003eblocks[0].ptr` as `xsize * ysize` tightly packed pixels, so exported data includes the padding bytes, and can include a few bytes from before the first row.\n\nTested vulnerable on 11.2.1, 12.3.0, 4c1ed27a5.\n\n### PoC\n\nWhether things leak may depend on allocator configuration. This does show a leak on my Mac.\n\n```python\nimport os\n\nos.environ[\"PILLOW_ALIGNMENT\"] = \"64\"\n\nfrom PIL import Image\n\n# Image A: 64 px wide, so its rows fill the whole aligned stride\na = Image.new(\"L\", (64, 40), 0x41).transpose(Image.Transpose.FLIP_LEFT_RIGHT)\ndel a\n\n# Image B: 61 px wide, so each row has 3 bytes of padding; its pixels are all 0\nb = Image.new(\"L\", (61, 40), 0).transpose(Image.Transpose.FLIP_LEFT_RIGHT)\n\ntry:\n    exported = Image.fromarrow(b, b.mode, b.size).tobytes()\nexcept ValueError as e:\n    print(\"Not vulnerable:\", e)\nelse:\n    if leaked := len(exported) - exported.count(0):\n        raise RuntimeError(f\"{leaked} of {len(exported)} exported bytes are not B's pixels\")\n```\n\n### Impact\n\nInformation disclosure for applications that set `PILLOW_ALIGNMENT` and export images to Arrow. Likely any image whose row length isn't a multiple of the alignment will do. In a service handling several users' images, one user's exported data can contain pixels from another user's image, or other stale heap contents.","status":"published","published":"2026-10-23T21:53:21Z","modified":"2026-10-29T10:56:00.934076155Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-226","CWE-908"],"updated_at":"2026-11-02T15:46:39.266402Z"},{"id":"PYSEC-2026-4336","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T22:16:49.41Z","modified":"2026-10-29T10:56:00.934076155Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:52:57.671918Z"},{"id":"UBUNTU-CVE-2026-114501","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-21T22:16:00Z","modified":"2026-11-04T20:03:34.586998859Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-04T21:44:25.758797Z"},{"id":"BIT-pillow-2026-114501","title":"Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT \u003e 1","description":"Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im-\u003eblocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.","status":"published","published":"2026-10-29T08:57:44.973Z","modified":"2026-10-29T10:56:00.934076155Z","updated_at":"2026-11-02T15:28:34.724063Z"},{"id":"CLSA-2026-1793025111","title":"TuxCare security update for pillow (3 CVEs)","description":"TuxCare rebuilt pillow to address 3 CVEs. Fixed in 11.3.0.post12+tuxcare.","status":"published","published":"2026-10-26T14:31:51Z","modified":"2026-10-27T01:45:03.425401243Z","updated_at":"2026-11-02T15:43:54.981307Z"},{"id":"CLSA-2026-1793101237","title":"TuxCare security update for pillow (1 CVE)","description":"TuxCare rebuilt pillow to address 1 CVE. Fixed in 11.2.1.post14+tuxcare.","status":"published","published":"2026-10-27T11:40:37Z","modified":"2026-10-27T13:30:19.347381291Z","updated_at":"2026-11-02T15:43:55.34846Z"},{"id":"openSUSE-SU-2026:22246-1","title":"Security update for python-Pillow","description":"This update for python-Pillow fixes the following issues:\n\n- CVE-2026-96636: decompression-bomb protection bypass via multi-frame `seek()` in MPO and DCX (bsc#1286802).\n- CVE-2026-96637: decompression bomb check bypass in `SpiderImagePlugin.seek()` leads to unbounded allocation DoS\n  (bsc#1286801).\n- CVE-2026-96638: BMP RLE decoder memory-amplification DoS via unbounded delta escape/absolute mode (bsc#1286800).\n- CVE-2026-96639: multi-frame loaders can reuse stale native image storage after mode transitions (bsc#1286799).\n- CVE-2026-96640: PDF append accepts malformed shared page-tree DAG, which can cause resource exhaustion (bsc#1286798).\n- CVE-2026-96641: reachable undefined behavior in native integer operations can lead to denial of service or logic\n  integrity compromise (bsc#1286797).\n- CVE-2026-96642: `TarIO` negative size field causes infinite CPU-spin loop (bsc#1286796).\n- CVE-2026-96643: PNG eXIf chunk makes EXIF parsing run in quadratic time (bsc#1286795).\n- CVE-2026-96778: heap buffer overflow writing JPEG comment after ICC profile fills buffer (bsc#1286793).\n- CVE-2026-112390: Denial of Service via infinite loop during crafted MIC image parsing (bsc#1286256).\n- CVE-2026-112391: Denial of Service via unbounded recursion in PDF parser (bsc#1286273).\n- CVE-2026-112392: Denial of Service via zero-size images in rank filters (bsc#1286287).\n- CVE-2026-112393: heap buffer overflow and stale-heap disclosure in _tiffWriteProc when saving compressed TIFF data\n  (bsc#1286325).\n- CVE-2026-112394: `P;2L` and `P;4L` decoders may read 1 to 3 bytes past the passed buffer size (bsc#1286311).\n- CVE-2026-112395: Pillow tiled-TIFF decoder reads past tile buffer in `copy4` (bsc#1286312).\n- CVE-2026-112396: heap use-after-free when encoding TIFF to an in-memory buffer (bsc#1286313).\n- CVE-2026-112397: out-of-bounds access in `_imagingmorph` on a zero-width image (bsc#1286314).\n- CVE-2026-112398: heap buffer overflow in FPX JPEG decoding can lead to code execution (bsc#1286406).\n- CVE-2026-112399: Denial of service via crafted APNG image (bsc#1286368).\n- CVE-2026-112400: Denial of Service via memory exhaustion from crafted GIF image (bsc#1286370).\n- CVE-2026-112401: Denial of Service via crafted GIF comments (bsc#1286372).\n- CVE-2026-112402: Denial of service via double free during image transformation (bsc#1286381).\n- CVE-2026-112403: heap buffer overflow in `ImagingJpegDecode` allows for code execution (bsc#1286405).\n- CVE-2026-112404: Denial of Service via out-of-bounds read in TIFF decoding (bsc#1286388).\n- CVE-2026-112405: NULL pointer dereference in `Image.merge` via an unvalidated band 0 (bsc#1286404).\n- CVE-2026-112406: infinite loop in `PdfParser.rewrite_pages` on page tree `Parent` cycle (bsc#1286403).\n- CVE-2026-112891: quadratic GIF comment copying during save (bsc#1286402).\n- CVE-2026-112892: MSP RLE decoder expands a tiny file into unbounded memory (bsc#1286401).\n- CVE-2026-112893: Denial of Service via invalid pointer free during font rendering (bsc#1286392).\n- CVE-2026-112894: Denial of Service via crafted multi-frame image conversion (bsc#1286408).\n- CVE-2026-112895: Denial of service via crafted PDF during append operations (bsc#1286411).\n- CVE-2026-112896: TIFF encoder `ColorMap` plane-size mismatch causes a heap out-of-bounds read (bsc#1286400).\n- CVE-2026-112897: `TiffDecode` returns uninitialized memory as pixels for short JPEG strips (bsc#1286398).\n- CVE-2026-112898: `Image.quantize()` with empty palette can leak uninitialized stack memory (bsc#1286399).\n- CVE-2026-112899: EPS `load(scale)` lets Ghostscript render past the decompression bomb limit (bsc#1286489).\n- CVE-2026-112900: argument Injection in Ghostscript call can lead to remote code execution (bsc#1286397).\n- CVE-2026-112901: ReDoS in `XbmImagePlugin` can be triggered by 512-byte file (bsc#1286396).\n- CVE-2026-112902: memory disclosure and segfault in libtiff encoder via crafted TIFF tags (bsc#1286804).\n- CVE-2026-114501: Arrow export leaks stale heap memory when `PILLOW_ALIGNMENT \u003e 1` (bsc#1286803).\n","status":"published","published":"2026-11-05T03:40:19Z","modified":"2026-11-11T17:23:13.17320283Z","updated_at":"2026-11-11T17:47:15.466074Z"}]}}